Numbers in solar terms

The latitude of the tangent point is between 66 34' and 90. According to the relationship between the latitude of the tangent point and the latitude of the direct point of the sun (the two are complementary), it can be known that when the latitude of the tangent point is 66 34', the straight line of the Tropic of Cancer is the summer solstice or the winter solstice; When the tangent latitude is 90, the sun shines directly at the equator, and the solar terms are vernal equinox or autumnal equinox. Therefore, we can determine the solar terms represented by the number ③ in the figure: the tangential latitude ③ is 66 34', and the solar terms should be summer solstice or winter solstice.

When the solar term represented by the number ③ is the summer solstice, the left tangent latitude 90 is the vernal equinox and the right tangent latitude 90 is the autumnal equinox. Looking at the map is determined according to the relative position of other numbers and the known solar terms: ① severe cold, ② long summer and ④ heavy snow.

When the solar term represented by the number ③ is the winter solstice, the left tangent latitude 90 is the autumnal equinox and the right tangent latitude 90 is the vernal equinox. Looking at the map is determined according to the relative positions of other figures and known solar terms: ① Summer, ② beginning of winter and ④ Miscanthus.

Therefore, choose: d.